Method and apparatus in unwinding

ABSTRACT

In the method in splicing in a continuous unwind, the surface speed of a new machine reel (R 2 ) which is brought to the unwind and closed with a leading splice is accelerated in the initial acceleration to make the speed correspond to the speed of the old machine reel (R 1 ) that is becoming empty, so that the fastening splice of the new machine reel can be joined to the web of the old machine reel. The loading affecting the leading splice and/or fastening splice of the new machine reel (R 2 ) during the initial acceleration is reduced. The present invention also relates to an apparatus for implementing the method.

[0001] The present invention relates to a method and apparatus inunwinding. The invention relates to a situation preceding the splicingstage in a continuous unwind, which terminates when the web of a newmachine reel brought to the unwind is attached at full speed to the webof a machine reel that is becoming empty, by pressing the web of themachine reel that is becoming empty against a splice in the new machinereel, and the old web has been cut. Unwinding devices and measuresconducted in connection with the reel change are described for examplein Finnish patents FI 100323 and FI 101875.

[0002] In this application, the term leading splice is used to describethe arrangement that keeps the web attached to the surface of a newmachine reel before splicing. The term fastening splice is used todescribe the arrangement that fastens the web of a new machine reel tothe web coming from the old machine reel that is becoming empty. Theleading splice and the fastening splice can form two discrete sections,or they can be parts of the same fastening arrangement. The leadingsplice and the fastening splice can, for example, form the differentsides of a two-sided adhesive tape, if the tape is attached to the endof the web of a new machine reel in such a manner that part of the tapeextends over the length of the web fixing the end of the web to the newmachine reel. In this application, the concept of a splicing gap refersto the point extending on the entire width of the web between the newmachine reel and the splicing roll, in which point the distance betweenthe new machine reel and the splicing roll is the shortest. In asplicing situation, the splicing gap is closed when the splicing rollstrikes against the surface of the new machine roll to attain splicing.Furthermore, in this application the term initial acceleration refers tothe stage of accelerating the speed of a full machine reel and/or therotation of the same before splicing.

[0003] In off-machine coating machines for paper, a continuous unwind isused in which a new, full machine reel that is brought to the unwind isattached to the end of the paper web in the machine reel that isbecoming empty. In present-day fast coating machines the splicing methodis essentially the same, i.e. a fastening splice is prepared in theleading end of the web of a new machine reel by means of a two-sidedadhesive tape, coated with a binding agent, the splice being attached onthe surface of the reel by means of a leading splice, for example withpieces of fastening tape. The surface speed of the new machine reel isaccelerated to be equal to the running speed of the machine, i.e. to theweb speed of the paper web discharged from the machine reel that isbecoming empty, whereafter the web of the reel that is becoming empty ispressed against the aforementioned fastening splice for example by meansof a roll or a brush. The old web is cut with a blade above the splice.

[0004] In the splicing, the splicing roll is rapidly struck against thesurface of a new machine reel, wherein a tension peak occurs in the web.The aim is to keep the tension peak caused by the stroke of the roll ona low level, by using a small splicing gap (8 to 12 mm), which causes astrong phenomenon of negative pressure. Because the present runningspeeds are very high, even over 1600 m/min, situations easily occur inwhich the travel of the web is disturbed and the web may break. Becausethe loading stressing the leading splice is directly proportional to thesquare of the running speed, and the adhesive attraction of thefastening splice is directly proportional to the adhesion time, which,of course, is reduced when running speeds are increased, it is obviousthat splicing is problematic at high running speeds.

[0005] The negative pressure which is generated in the splicing gapbetween the splicing roll and the machine reel tends to draw the old webpartly against the fastening splice already before splicing. Thenegative pressure may be pulsating when the new machine reel is out ofround. Furthermore, the negative pressure tends to detach the leadingsplice from the surface of the new machine reel, wherein the new machinereel is unwound before splicing.

[0006] One solution for stabilizing the run of the web is presented inthe patent publication U.S. Pat. No. 5,779,184 and in the correspondingEuropean publication 0732287. By means of the method according to thepublication, the run of the web is stabilized in such a manner thatbefore the splicing gap there is a suction box, equal in width with theweb, and the web touches this suction box when passing by the same. Thesuction is directed away from the web, wherein the negative pressurekeeps the web on the surface of the suction box, thereby stabilizing itsrun. By means of this arrangement, it is not, however, possible toeliminate all effects of the negative pressure in the splicing gap.

[0007] It is an aim of the solution of the present application that theend of a new machine reel remains attached to the surface of a newmachine reel by its leading splice, and that the new machine reelendures the initial acceleration without being unwound. On the otherhand, the leading splice has to be detached easily when the splicingroll is struck against the surface of the new machine reel, and thefastening splice adheres to the web coming from the old machine reelthat is becoming empty, the old web is cut and the discharge of the webfrom the new machine reel begins. A substantially uniform loading isexerted on the leading splice on the entire width of the web, whichloading can, however, vary as a function of time for example due to saidpulsating negative pressure. The loading exerted on the leading spliceconsists of the loading caused by air friction, centrifugal tension andthe tension caused by the negative pressure in the splicing gap. Inaddition, the fastening splice must have a good adherence capacity tothe web. Most significant part of the loading that exerted on theleading splice is the tension caused by the negative pressure prevailingin the splicing gap.

[0008] The tension caused by air friction can be calculated according tothe following formula

T _(fric)={fraction (1/2)}·C _(f)·ρ_(a) ·V ² ·I,

[0009] in which

[0010] T_(fric)=tension caused by air friction (N/m)

[0011] C_(f)=coefficient of resistance ˜0,0025

[0012] ρ_(a)=air density (kg/m³)

[0013] v=running speed (m/s)

[0014] l=web length (m)

[0015] The centrifugal tension can be calculated according to theformula

T _(CP)=(M _(WEB) +M _(AIR))·V ²,

[0016] in which

[0017] T_(CP)=centrifugal tension (N/m)

[0018] M_(WEB)=grammage of paper (kg/m²)

[0019] M_(AIR)=mass of air conveyed by paper (kg/m²)

[0020] v=running speed

[0021] The tension caused by the negative pressure prevailing in thesplicing gap is calculated according to the formula

T _(VAC) ≈Δp·r,

[0022] in which

[0023] T_(VAC)=tension caused by negative pressure (N/m)

[0024] Δp=the difference between the pressure of the splicing gap andthe pressure prevailing inside the reel (normal pressure), i.e. thenegative pressure (Pa) prevailing in the splicing gap

[0025] r=radius of the reel to be accelerated (m)

[0026] The negative pressure prevailing in the splicing gap iscalculated according to the formula

Δ≈{fraction (1/2)}·ρ_(a) ·v _(a) ²,

[0027] in which

[0028] ρ_(a)=air density (kg/m³)

[0029] v_(a)=flow rate of air in the splicing gap (m/s)

[0030] By means of the method and apparatus according to the inventionit is possible to affect the loading exerted on the leading spliceand/or fastening splice of the new machine reel. The method ischaracterized in that the loading affecting the leading splice and/orfastening splice of the new machine reel during the initial accelerationis reduced. The apparatus is characterized in that it comprises meansfor reducing the loading applied to the leading splice and/or fasteningsplice of the new machine reel.

[0031] By means of the new high speed splicing arrangement according tothe invention, it is possible to considerably reduce the loading exertedon the leading splice and/or fastening splice, especially the negativepressure prevailing in the splicing gap. Furthermore, it is possible toadjust the temperature of the leading splice and/or fastening splice toadjust their adhesion.

[0032] The effect of the loading exerted on the leading splice and/orfastening splice, for example the tension caused by air friction and thetension prevailing in the splicing gap, can be reduced by passive and/oractive actuators. By means of active actuators the loading is reduced byproducing counter loading for said loading, and the passive actuatorsfunction as obstacles so that the air current causing the negativepressure would not enter the splicing gap. Generally, the actuatorsextend over the entire width of the web, but it is also possible thatthe actuators only extend on a part of the width of the web.

[0033] To reduce the tension caused by the negative pressure prevailingin the splicing gap, the aim is to reduce or prevent the generation ofnegative pressure. The generation of negative pressure can be preventedor it can be reduced for example

[0034] by directing an air blow in the splicing gap, the direction ofwhich is substantially opposite to the flow direction of the air flowingin the splicing gap. The amount of air blow is adjusted so that the flowrate of air in the splicing gap is approximately substantially zero, or

[0035] by arranging moving or stationary mechanical obstacles, whichprevent or reduce the generation of negative pressure in the splicinggap, or

[0036] by directing air suction away from the splicing gap, thedirection of which is substantially opposite to the flow direction ofthe air flowing in the splicing gap. The amount of air suction isadjusted so that the flow rate of air in the splicing gap isapproximately substantially zero, or

[0037] by blowing air along the surface of a new, full machine reelagainst the direction of rotation of the machine reel and/or by blowingair along the surface of a web coming from the old machine reel that isbecoming empty against the travel direction of the web.

[0038] The adhesion of the fastening splice to the web of the oldmachine reel can be improved by adjusting the temperature of the ambientair in the fastening splice and/or the temperature of the fasteningsplice. The temperature of the ambient air in the fastening spliceand/or the temperature of the fastening splice can be increased by meansof infrared heating, by blowing heated air from a blow box or the like,by microwave heating or inductively by heating up the fastening splicethat contains metal. The act of reducing the negative pressure in thesplicing gap and the heating of the fastening splice can be combined inone actuator in such a manner that the blowing of the heated air isarranged to a suitable location from which air is blown to reduce theair flow in the splicing gap.

[0039] The effect of the tension caused by air friction can be reducedby directing air blows to suitable points in the direction of theperiphery of the new machine reel and in the direction of rotation ofthe reel within a given section on the periphery, that does not extendclose to the splicing gap, in the vicinity of which air is blownsubstantially against the aforementioned direction.

[0040] In the following, the invention will be described with referenceto the appended drawings, in which,

[0041]FIG. 1 shows a side-view of a full machine reel,

[0042]FIG. 2 shows an unwinding apparatus and an embodiment of theinvention,

[0043] FIGS. 3 to 7 shows embodiments of the invention, and

[0044]FIG. 8 shows an arrangement to reduce air friction.

[0045]FIG. 1 shows a side-view of a full machine reel R2 that enters theunwind. The drawing also shows as an example how leading splices andfastening splices can be formed on the surface of the full machine reelR2. The paper web is reeled around a reeling shaft K, and the end E ofthe paper web W (marked with a dotted line in the drawing) is attachedto the surface of the reel R2 by means of a leading splice P. The end Eof the paper web W remains underneath the splices according to FIG. 1.On the surface of the reel R2 there is a ready-made fastening splice F,from which the new machine reel R2 is attached to the end of the web Wof an old machine reel R1.

[0046]FIG. 2 shows a side-view of an apparatus whose splicingarrangement is of the type presented in the Finnish patent 100323. Inthe apparatus, the web W is continuously unwound from machine reelsbrought to thereto, said machine reels being formed at an earlierreeling stage, and the web W is guided to a finishing apparatus of paperweb, for example to a coating machine. The apparatus comprises asecondary drive 2 which rotates the machine reel R1 that is becomingempty and a primary drive 1 which rotates a new, full machine reel R2brought to the apparatus. The main principle of the continuous unwindingis to bring reels successively into the apparatus in such a manner thata full reel is brought therein to be rotated by the primary drive 1, thepaper web of the reel is attached to the web W coming from the reel thatis becoming empty, which is rotated by the secondary drive 2, and theweb is cut, whereafter it is unwound from the full reel rotated by theprimary drive 1. When a particular amount of paper remains on the reelrotated by the primary drive 1, the reel is transferred to be rotated bythe secondary drive 2, and a new full machine reel is brought to theprimary drive, whereafter the webs are attached to each other again inthe above-described manner. The transfer of the full reel R2 to theprimary drive 1, the removal of the empty reel R1 from the secondarydrive 2 and the change of the unwound reel from the primary drive 1 tothe secondary drive 2 can be performed by using known solutions, andsince they are not part of the invention, they will not be described inmore detail in this context.

[0047]FIG. 2 describes a situation before the change, in which the webof the full machine reel R2 that has been brought to a primary stationin the primary drive 1 is joined to a web W discharged from the machinereel R1 that is becoming empty in the secondary drive 2. Thecircumference of the full machine reel R2 touches a splicing stationprovided with a splicing roll 3 which guides the web W discharged fromthe reel R1 that is becoming empty in close proximity to the outersurface of the circumference in the full machine reel R2 rotated by theprimary drive 1, in such a way that a splicing gap of a given width isformed between the web and the machine reel R2. The splicing isperformed by striking the splicing roll 3 rapidly towards the oppositesurface of the reel, wherein the splicing gap is closed. The splicingstroke is synchronized by striking the web W against the surface of thefull machine reel R2 when the attachment point on the surface of thereel, for example a splicing tape, enters the splicing station. Thispoint is marked with the letter S. The tape assembly in question can befor example a tape assembly in the transverse direction of the web bymeans of a tape whose both sides are adhesive, the tape assembly beingattached to the end of the web of a full machine reel R2, and ittypically has the shape of a saw blade or the like for the purpose ofimproving the grip. Furthermore, the cutting of the web to be dischargedis conducted in a synchronized manner with the splicing stroke byutilizing a cutting device illustrated by arrow C, which cutting deviceperforms the cutting stroke and is located before the splicing roll 3 inthe travel direction of the web. The cutting device can be for example astriking blade cutting device. The drawing also illustrates an auxiliaryroll 4 cooperating with the actual splicing roll 3 and guiding thedischarged web W after the splicing station (splicing gap). Theauxiliary roll is attached together with the splicing roll 3 to a commonlever 5 articulated at an articulation point 5 a located between theaxes of the rolls 3 and 4. When the splicing roll 3 is struck againstthe surface of the full machine reel R2 by means of an actuator (notshown), the motion is transmitted to the auxiliary roll 4 by means ofthe lever, this motion of the auxiliary roll backwards along a pathdetermined by the point of articulation compensating the stretchotherwise produced on the web.

[0048]FIGS. 2 and 3 show an embodiment of the invention, in which air isblown to the splicing gap N from a blow device 6. From the blow device 6installed in the gap opening between the reel and the web, air is blownin the direction of the arrow B towards the splicing gap N against thetravel direction of the periphery of the reel R2 and the web W. Duringsplicing, a contact point N1 on the periphery of the splicing roll 3 anda contact point N2 on the periphery of the new machine reel R2 enter incontact with each other. The points N1 and N2 extend over the length ofthe splicing roll 3 and over the entire width of the web W. In a normalrunning situation there is a splicing gap N between these contact pointsN1 and N2 that extend over the entire width of the web W. The blow ofair is parallel to the tangent on the periphery of the splicing roll 3that travels via the point N1 and the tangent on the periphery of thenew machine reel R2 that travels via the point N2, and it issubstantially directed towards the splicing gap N between the points N1and N2. Air is blown at such a speed that the flow rate in the splicinggap is substantially zero. Air is blown on the entire width of the webfrom a slit orifice or the like, at a speed which substantially equalsthe travel speed of the web W. Thus, it is advantageous that the airinlet of the blow device 6 is equal in size with the splicing gap N. Theblow device 6 is connected to a positive pressure air source, forexample to an air compressor. The blast pressure of the blow device 6can be set as a function of the running speed, i.e. the travel speed ofthe web W.

[0049]FIG. 2 also shows an arrangement by means of which it is possibleto measure and adjust the temperature of the air to be blown to improvethe adhesion of the fastening splice or to adjust the adhesion of theleading splice and/or fastening splice. A temperature sensor 12 measuresthe temperature on the surface of the machine reel R2 and the adjustmentdevice 13 for temperature is arranged to adjust the temperature of theair to be blown on the basis of the information obtained from thetemperature sensor 12. The temperature sensor 12 and the adjustmentdevice 13 for temperature are known as such, and therefore they will notbe described in more detail in this context. The binding agents of theleading splices and fastening splices can be selected in such a mannerthat their adhesion is different in the same temperature, wherein thesplices behave optimally in the splicing situation. For example theadhesion of the fastening splice may be greater than the adhesion of theleading splice in said temperature. The temperature of the air to beblown can also be changed during the period of time passed between theact of starting the initial acceleration and the splicing. Thus, the airflow blown from the device 6 can be utilized to affect both the flowconditions and the temperature conditions in the splicing gap.

[0050]FIG. 4 shows an embodiment of the invention, in which mechanicalobstacles 7 are placed above and below the splicing gap to prevent thegeneration of negative pressure. The cross-section of the obstacles 7can, for example, resemble the one shown in FIG. 4, but obstacles ofother shapes are also possible. The cross-section of the obstacles 7shown in FIG. 4 has a shape of the letter V with a rounded angle. Theobstacles 7 are located above and below the splicing gap, i.e. in thetravel direction of the periphery of the reel R2 and the web W beforethe splicing gap N and after the splicing gap N. The ends of theobstacles, whose cross-section has the shape of the letter V with arounded angle, are directed towards the splicing gap N, close to thespace between the points N1 and N2. One side of the obstacle 7 is closeto the surface of the new machine reel R2 and the other is close to thesurface of the web W. This way it is possible to reduce air flow in thesplicing gap, and thereby also the negative pressure. The obstacles maybe stationary or movable, wherein they can be transferred away fromtheir position after the splicing is finished, or the position of thesame can be changed for example when the size of the machine reelchanges. The number of the obstacles may vary, and they extend over theentire width of the web W.

[0051]FIG. 5 shows an embodiment, in which a moving obstacle is placedbefore the splicing roll 3 on the opposite side of the web W in thetravel direction of the web W, which obstacle prevents or reduces thegeneration of negative pressure in the splicing gap N. The obstacle is aroll 8 which has a considerably smaller diameter than the splicing roll3, and it extends over the entire width of the web W. The roll 8 touchesthe web W when the web travels passes by the roll 8. The direction ofrotation of the roll 8 is opposite to the direction of rotation of thesplicing roll 3, and at the point closest to the new machine reel R2,the surface of the same moves to a direction opposite to the directionof motion of the surface of the machine reel, thereby preventing theflow of air towards the splicing gap in the direction of the peripheryof the reel R2.

[0052]FIG. 6 shows an embodiment, in which air is sucked from thesplicing gap at a suitable flow rate in such a manner that the flow rateof air in the splicing gap N is substantially zero. The suction can beperformed by means of a suction device 9 extending over the entire widthof the web, for example by means of a slit orifice or the like. Thesuction device is positioned in the closing gap formed by the reel andthe web, close to the splicing gap N, in such a manner, however, that itdoes not touch the new machine reel R2, the splicing roll 3 or the webW. The slit orifice or corresponding suction inlet/inlets are directedtowards the splicing gap. The suction is directed in such a manner thatit is parallel to the tangent on the periphery of the splicing roll 3travelling via the point N1 and the tangent on the periphery of the newmachine reel R2 travelling via point N2, and it is substantiallydirected away from the splicing gap N between the points N1 and N2. Theslit orifice or a corresponding structure extends substantially over theentire width of the web. In FIG. 6 the direction of the suction is shownwith an arrow A. The suction device 9 is coupled to a negative pressureair source, for example to a vacuum pump.

[0053]FIG. 7 shows an embodiment in which air is blown in the directionsshown by arrows B1 and B2, substantially in parallel to the surface ofthe machine reel R2 and the web W in such a manner that the blowingtakes place against the direction of rotation of the machine reel R2,and against the travel direction of the web W. The blowing arrangement10 can be for example a slit orifice or the like, which is directed in asuitable manner and extends substantially on the entire width of theweb. The air currents B1 and B2 prevent the access of air currentsaccompanying the surface of the reel and the web to the splicing gap.

[0054]FIG. 8 shows an embodiment the aim of which is to reduce airfriction. Outside the outer periphery of the new machine reel R2, closeto the surface of the reel, devices 11 have been arranged at fixedintervals, which devices blow air in the direction of rotation of themachine reel R2 and extend over the entire width of the new machine reelR2. In FIG. 8, arrows B3 represent the direction in which air is blown.The air blowing devices 11 are basically of the same type with the blowarrangement 10, but they can differ from each other as far as theiroperating parameters, for example the flow rate of air or mass flow areconcerned. As can be seen in FIG. 7, there are several successive blowdevices on the sector of the periphery of the reel that beginsapproximately at an angular distance of 180° from the splicing gap andends at a distance of approximately 30° from the same. The blow devicesare not normally located in the splicing gap. The blow rate of air isadvantageously substantially the same as the speed of the web to beunwound.

[0055] The above-described facts do not restrict the invention, but theinvention may vary within the scope of the claims. The mechanicalobstacles can differ from those presented in this application. Theeffect can also be produced solely by means of an obstacle/obstacleslocated before the splicing gap or solely by means of anobstacle/obstacles located after the splicing gap. The blowing orsuction of air can be directed in different ways. The essential aspectis that the loading exerted on the leading splice and/or fasteningsplice of the new machine reel during the initial acceleration isreduced by means of an apparatus which is suitable for this purpose.

1. A method in splicing in a continuous unwind, in which method thesurface speed of a new machine reel (R2) which is brought to the unwindand closed with a leading splice is accelerated in the initialacceleration to make its speed correspond to the speed of an old machinereel (R1) that is becoming empty, so that the fastening splice of thenew machine reel can be joined to the web of the old machine reel,characterized in that the loading affecting a leading splice and/orfastening splice of the new machine reel (R2) during the initialacceleration is reduced by using active and/or passive actuators.
 2. Themethod according to claim 1, characterized in that the loading isreduced by directing air blows and/or suction to suitable locations. 3.The method according to claim 2, characterized in that air is blowntowards a splicing gap (N).
 4. The method according to claim 3,characterized in that air is blown between contact points (N1, N2)restricting the splicing gap in such a manner that the air blow issubstantially parallel to a tangent travelling via a contact point (N1)on the periphery of the splicing roll (3) and a tangent travelling via acontact point (N2) on the periphery of the new machine reel (R2).
 5. Themethod according to claim 2, characterized in that air is sucked fromthe splicing gap (N).
 6. The method according to claim 5, characterizedin that air is sucked between contact points (N1, N2) restricting thesplicing gap in such a manner that the suction of air is substantiallyparallel to a tangent travelling via a point (N1) on the periphery ofthe splicing roll (3) and a tangent travelling via a point (N2) on theperiphery of the new machine reel (R2).
 7. The method according to claim2, characterized in that the blow of air is directed in parallel to thesurface of the new machine reel (R2) against the direction of rotationof the machine reel.
 8. The method according to claim 2 or 7,characterized in that the blow of air is directed in parallel to the web(W) coming from the old machine reel (R1) against the direction ofrotation of the web.
 9. The method according to claim 2, characterizedin that the blow of air is directed in parallel to the outer peripheryof the new machine reel (R2) close to the surface of the machine reel inthe direction of rotation of the machine reel.
 10. The method accordingto claim 2, characterized in that the flow of air is affected before thesplicing gap (N) and/or after the splicing gap (N) by means ofmechanical obstacles.
 11. The method according to claim 10,characterized in that the obstacle is an article (7) shaped into a givenform from a sheet-like material.
 12. The method according to claim 10,characterized. in that the obstacle is a roll (8) arranged before thesplicing gap, which roll touches the web (W) when the web passes by theroll.
 13. The method according to claim 1, characterized in that thetemperature of the fastening splice and/or leading splice is adjusted toincrease the adhesion of the splices.
 14. An apparatus in connectionwith splicing of a web (W) coming from an old machine reel (R1) and aweb of a new machine reel (R2), in which splicing said webs are arrangedto be connected to each other by means of a fastening splice,characterized in that the apparatus comprises means for reducing theloading applied to the leading splice and/or fastening splice of the newmachine reel (R2).
 15. The apparatus according to claim 14,characterized in that the means for reducing the loading applied to theleading splice and/or fastening splice of the new machine reel (R2)comprise one or more active or passive actuators.
 16. The apparatusaccording to claim 14 or 15, characterized in that the device/devicesis/are one or more devices that blow or suck air.
 17. The apparatusaccording to claim 16, characterized in that the device is a blow device(6) which is positioned after the splicing gap and directed towards thesplicing gap against the travel direction of the surface of the newmachine reel (R1) and the web (W).
 18. The apparatus according to claim17, characterized in that the blow device (6) is arranged to blow airtowards the splicing gap (N) between the contact points (N1, N2) in sucha manner that the blow of air is substantially parallel to a tangenttravelling via a contact point (N1) on the periphery of the splicingroll (3) and a tangent travelling via a contact point (N2) on theperiphery of the new machine reel (R2).
 19. The apparatus according toclaim 16, characterized in that the device is a suction device (9) whichis located after the splicing gap and directed towards the splicing gapagainst the travel direction of the surface of the new machine reel (R2)and the web (W).
 20. The apparatus according to claim 19, characterizedin that the blow device (9) is arranged to suck air from the splicinggap between the contact points (N1, N2) in such a manner that thesuction of air is substantially parallel to a tangent travelling via acontact point (N1) on the periphery of the splicing roll (3) and atangent travelling via a contact point (N2) on the periphery of the newmachine reel (R2).
 21. The apparatus according to claim 16,characterized in that one or more devices are arranged to blow airbefore the splicing gap in parallel to the surface of the new machinereel (R2) against the direction of rotation of the machine reel.
 22. Theapparatus according to claim 16 or 21, characterized in that the blow ofair is directed in parallel to the web (W) coming from the old machinereel (R1) against the travel direction of the web.
 23. The apparatusaccording to claim 16, characterized in that one or more devices arearranged to blow air in parallel to the outer periphery of the newmachine reel (R2) close to the surface of the machine reel in thedirection of rotation of the machine reel.
 24. The apparatus accordingto claim 14 or 15, characterized in that one or more device/devicesis/are one or more mechanical obstacles placed between the splicing gapand/or after the splicing gap.
 25. The apparatus according to claim 24,characterized in that the obstacle is an article (7) shaped into a givenform from a sheet-like material.
 26. The apparatus according to claim24, characterized in that the obstacle is a roll (8) arranged before thesplicing gap, which roll touches the web (W) when the web passes by theroll.
 27. The apparatus according to claim 14, characterized in that itcomprises means for adjusting the temperature of the fastening spliceand/or leading splice.